1. Field of the Invention
The present invention relates to a recording tape cartridge such as a magnetic tape cartridge, for example, a digital data storage (DDS) and a digital video cassette or a digital video cartridge (DVC).
More specifically, the present invention relates to a recording tape cartridge which helps to reduce the component assembly man-hours at the time of assembly and to save the trouble of separation at the time of disposal, thus reducing the load to the environment.
Still more specifically, the present invention relates to a recording tape cartridge in which it is easy to assemble and mount members forming a lock mechanism for a tape reel accommodated in a case body and which is advantageous in terms of separated recovery of the resin material at the time of disposal.
2. Description of the Related Art
Recording media cartridges conventionally used as recording media for external storage devices such as computers are roughly classified into two types: ones using magnetic disks or magneto-optical disks as the recording media (magnetic or magneto-optical disk cartridges, etc.), and ones using magnetic recording tapes such as recording tapes or magnetic tapes (recording tape cartridges such as magnetic tape cartridges). A magnetic tape cartridge is used as a large-capacity recording medium for data backup in the above-mentioned external storage device; it has a case body (also referred to as case housing) composed of upper and lower halves and rotatably accommodating a tape reel around which a magnetic tape is wound. The magnetic tape cartridge includes a cartridge of the type in which a magnetic tape is wound around a single tape reel (the so-called one-reel type magnetic tape cartridge), and a cartridge of the type in which a magnetic tape is wound around two tape reels (the so-called two-reel type magnetic tape cartridge or magnetic tape cassette).
Such magnetic or magneto-optical disk cartridge, the magnetic tape cartridge, or the magnetic tape cassette (hereinafter collectively referred to as “magnetic tape cartridge” or “recording tape cartridge”) is used to store data in computers or the like; since important information is recorded therein, it is provided with various protective mechanisms in order to prevent damage to the magnetic or magneto-optical disk, generation of jamming in the magnetic tape or the recording tape, or inadvertent drawing out of the magnetic tape.
Specifically, to protect the magnetic tape when the magnetic tape cartridge is not loaded to the recording/reproducing apparatus (deck), that is, when the magnetic tape cartridge is stored or being carried about, there are provided a lid covering the front side of the magnetic tape cartridge, and a reel lock mechanism for preventing (locking) rotation of the tape reel (hereinafter simply referred to as the reel) for preventing slackening of the magnetic tape. These will be described below.
First, an ordinary conventional two-reel type magnetic tape cartridge provided with a reel lock member as a reel lock mechanism will be described.
FIG. 16 is an exploded perspective view of an ordinary conventional magnetic tape cartridge.
As shown in FIG. 16, the case body of a magnetic tape cartridge 100 is formed by joining together an upper half 102 and a lower half 104, and between them (i.e., in the case body), there is accommodated a magnetic tape 108 wound around a supply reel 106a and a take-up reel 106b. 
To the front side of the upper half 102, there is mounted a lid (front cover) 110 for covering the magnetic tape 108 when the magnetic tape cartridge 100 is not being used so as to be rotatable around a pin (not shown).
To prevent slackening of the magnetic tape 108 wound around the supply reel 106a and the take-up reel 106b when the magnetic tape cartridge is not being used, there are arranged reel lock (brake) members 112a and 112b in a condition in which they are urged by springs.
Further, provided on the lower half 104 is a lock mechanism (lid lock mechanism described in detail below) which locks the lid 110 so as to prevent it from opening when the magnetic tape cartridge is not being used and which is formed by a lid lock member 124, etc. The lid lock mechanism is usually only provided for one end of the lid 110.
FIG. 17 is a perspective view of one end portion (the end portion provided with the lid lock mechanism as described below), which is the right end portion in the example shown. As shown in FIG. 17, a shaft (lid pin) 114 is provided on the inner side of a side surface of the lid 110. Then, the lid 110 is mounted to the upper half 102 so as to be rotatable around the shaft 114 as indicated by the arrow A.
Further, the shaft 114 is provided with a reel lock releasing key 116 in the form of a protrusion. Further, in the side surface of the lid 110, there is provided a hole (lid lock hole) 118 for receiving a component (lid lock key 128 described in detail below) for locking the lid 110 to prevent it from inadvertently opening when the magnetic tape cartridge is not being used.
FIG. 18 is an enlarged perspective view of a reel lock member 112b and components around the same.
As shown in FIG. 18, the central portion of the reel lock member 112b is fitted onto a pin 120 and supported so as to be rotatable around the pin 120; one end portion of it is formed by a wall-like member 113a, and the other end portion thereof is formed by a claw-like member (braking claw) 113b; the braking claw 113b is engaged with an engagement tooth 107 provided in the flange peripheral edge of the reel 106b to thereby regulate the rotation of the reel 106b and prevent the magnetic tape from slackening.
Normally, the reel lock member 112b is urged by a coil spring 122 toward a position where the braking claw 113b is engaged with the engagement tooth 107.
Further, in the vicinity of the reel lock member 112b, a lid lock member 124 is arranged. One end portion 124a of the lid lock member 124 is fitted onto a pin 126 and is thereby anchored. The lid lock member 124 is rotatable around the pin 126, and on the other end portion 124b thereof, there is provided a lid lock key 128 in the form of a protrusion. As shown in FIG. 16, this lid lock key 128 protrudes outwardly through a hole 104a provided in the side wall of the lower half 104, and is engaged with a lid lock hole 118 provided in the side wall of the lid 110 shown in FIGS. 16 and 17 to regulate (lock) the lid 110 so as to prevent it from rotating.
As shown in FIG. 18, normally (when the magnetic tape cartridge is not being used), the lid lock member 124 is urged by (the other) end portion of the coil spring 122 urging the reel lock member 112b, and the lid lock key 128 is engaged with the lid lock hole 118 of the lid 110 to thereby lock (brake) the lid 110 so as to prevent it from rotating.
When the magnetic tape cartridge 100 has been loaded to the recording/reproducing apparatus (deck, not shown), a member on the deck side pressurizes the lower portion of the end portion 124b of the lid lock member 124 in the direction indicated by the arrow B of FIG. 18, whereby the end portion 124b of the lid lock member 124 rotates in the direction indicated by the arrow C of FIG. 18. This causes the lid lock key 128 to be released from the engagement with the lid lock hole 118 of the lid 110, making the lid 110 rotatable in the direction of the arrow A of FIG. 19.
When the lid 110 thus rotates in the direction of the arrow A in FIG. 19, the shaft 114 also rotates in the direction of the arrow A as shown in FIG. 19, whereby the reel lock releasing key 116 provided on the shaft 114 urges a wall-like portion 113a of the reel lock member 112b in the direction of the arrow D. As a result, the reel lock member 112b rotates around the pin 120, and the braking claw 113b provided at one end thereof moves in the direction indicated by the arrow E in FIG. 18, whereby the engagement of the reel 106b with the engagement tooth 107 is released, thereby making the reel 106b rotatable.
Next, a conventional ordinary one-reel type magnetic tape cartridge provided with a reel lock (braking) member as a reel lock mechanism will be described.
FIG. 20 is an exploded perspective view of a conventional magnetic tape cartridge.
A magnetic tape cartridge 204 shown in FIG. 20 includes a case body formed by joining together an upper half 200 and a lower half 202; a magnetic tape 214 is wound around a tape reel (reel) 212 comprised of a reel hub 206 and an upper flange 208 and a lower flange 210 provided on top of and beneath the reel hub 206, and this reel 212 is rotatably accommodated in the case body.
In the outer peripheral edge of the upper flange 208, there are provided engagement teeth 219 adapted to be engaged with braking claws 218a and 218b of reel lock members 216a and 216b arranged on the inner surface of the upper half to regulate the rotation of the reel 212 and prevent slackening of the magnetic tape when the magnetic tape cartridge 204 is not being used. As an example of the reel lock members, the reel lock member 216a will be described. As shown in FIG. 21, it has a cylindrical fitting shaft portion 224 rotatably fitted onto a center rod 222 provided on the inner surface 220 of the upper half 200, and an engagement arm portion 226 and a releasing arm portion 228 extending radially outwards from the outer peripheral surface of the fitting shaft portion 224.
The engagement arm portion 226 is arranged so as to extend along the outer periphery of the upper flange 208 of the reel 212, and the releasing arm portion 228 is arranged so as to face an opening 232 formed in a side wall 230 of the upper half 200. Then, at the forward end of the engagement arm portion 228, there are formed braking claws 218a to be engaged with engagement teeth 219 formed in the outer peripheral edge of the upper flange 208.
In the reel lock member 216a, the braking claws 218a of the engagement arm portion 226 are urged toward the center axis of the upper flange 208 by a torsion spring 236 which is fitted onto the lower portion of the center rod 222 and whose leg portions 234a and 234b respectively abut the side wall 230 of the upper half 200 and the engagement arm portion 226. Due to this arrangement, the braking claws 218a of the reel lock member 216a are urged such that they are normally engaged with engagement teeth of the upper flange 208, whereby rotation of the reel 212 is regulated when the magnetic tape cartridge 204 is not being used, thereby preventing slackening of the magnetic tape.
As to the releasing arm portion 228, when the magnetic tape cartridge 204 is loaded to a recording/reproducing apparatus, a releasing means of this apparatus enters the case body through the opening 232 to pressurize the releasing arm portion 228, and causes the reel lock member 216a to rotate in the direction of the arrow X around the center rod 222, whereby the engagement of the braking claws 218a with the engagement teeth 219 is released.
When the magnetic tape cartridge 204 is extracted from the recording/reproducing apparatus, the pressurization of the releasing arm portion 228 by the above-mentioned releasing means is released, and the reel lock member 216a is rotated around the center rod 222 by the torsion spring 236, whereby the braking claws 218a are engaged with engagement teeth 219, and the rotation of the reel 212 is regulated (braked), thereby preventing slackening of the magnetic tape.
While the reel lock member 216a has been described as an example, the reel lock member 216b also has a similar construction and operations in a similar manner.
Next, a conventional ordinary two-reel type magnetic tape cartridge provided with a reel lock member as a reel lock mechanism of a construction different from that of the magnetic tape cartridge shown in FIG. 16 will be described.
FIG. 22 is an exploded perspective view of the construction of a conventional ordinary magnetic tape cartridge.
A magnetic tape cartridge 310 shown in FIG. 22 includes a case body which is formed by joining together an upper half 320 and a lower half 322 each having a bottom plate and a peripheral plate; accommodated between them (i.e., in the case body) is a magnetic tape 326 wound around supply and take-up tape reels (reels) 324.
Planar shifting of the reels 324 is regulated by a plurality of regulating ribs provided on the bottom plate 322a of the lower half 322 so as to be along the outer peripheries of the reels. Further, in the bottom plate of the upper half 320, there is provided an opening making it possible to check the winding amount of the magnetic tape 326 on the reels 324, and a transparent window (inspection window) 320a is provided so as to close this opening.
Further, on the inner surface of the upper half 320 (the lower surface in the drawing), a pair of reel urging plate springs (reel presser springs) 338 are provided respectively for the reels. The reel presser springs 338 are fastened to the inner surface of the upper half 320 in a cantilever-like fashion by welding, caulking, screwing, etc., and urge the reels 324 toward the lower half 322.
Mounted to the front surface (the left-hand side in the drawing) of the upper half 320 is a lid for covering and protecting the magnetic tape 326 when the magnetic tape cartridge 310 is not being used. As described below, this lid is composed of three members: an outer lid 330, an upper lid 332, and an inner lid 334, each being mounted so as to be capable of opening and closing an opening 328 of the magnetic tape cartridge.
Tape guides 346 are provided on protrusions 340 on either side of the opening 328 on the front end side (front side in the figure) of the lower half 322. The tape guides 346 guide the magnetic tape 326 fed from one reel 324 and taken up by the other reel 324 and cause the magnetic tape 326 to pass a predetermined position in the opening 328.
Further, mounted to the rear end (the back side in the drawing) of the lower half 322 is a reel lock member (also referred to as the tape reel lock member) having tape reel anchoring arms (hereinafter simply referred to as the anchoring arms) 336a and a slide body portion 336b. The slide body portion 336b is slidably held by a pair of guide ribs provided on the bottom plate 322a of the lower half 322. As described below, this reel lock member 336 is urged by a compression coil spring 342, whereby the anchoring arms 336a are engaged with engagement teeth 324a formed in the outer peripheries of the lower flanges of the reels 324, thereby preventing inadvertent rotation of the reels 324. This helps to prevent slackening, etc. of the magnetic tape 326.
Of the outer lid 330, the upper lid 332, and the inner lid 334 mounted to the upper half 320, the outer lid 330 has a flat portion and a side plate, on the inner side of which there is provided a lock pin 348. Then, a lid lock member 344 for anchoring the lock pin 348 of the outer lid 330 in the closed state is rotatably mounted to a side wall portion 322c which is a part of the peripheral wall of the lower half 322. This lid lock member 344 is urged so as to anchor the lock pin 348 by a lid lock spring (not shown) that is also mounted to the lower half 322.
Further, mounted to the lower half 322 is an erroneous erasure preventing plug 352 for preventing the data recorded on the magnetic tape 326 from being erroneously erased. On one side surface (back side surface in the figure) of the erroneous erasure preventing plug 352, there is provided a claw portion, which, when mounted to the lower half 322, protrudes outwards through an opening provided in the peripheral wall of the upper half 320.
Then, by operating this claw portion from outside, it is possible to move the erroneous erasure preventing plug 352 along a guide rib standing upright on the bottom plate 322a of the lower half 322. With the bottom surface of this erroneous erasure preventing plug 352, it is possible to close and open an inspection hole provided in the bottom plate of the lower half 322; an apparatus, such as a recording apparatus, can read the condition of this inspection hole, making a judgment as to whether it is possible to write new data to the magnetic tape 326.
The lower half 322 has a rectangular bottom plate 322a, which rotatably supports the pair of reels 324 around which the magnetic tape 326 is wound, and which has reel spindle insertion holes 322b for inserting reel spindles (not shown) of the recording/reproducing apparatus into the reels 324 to rotate the reels 324 when the magnetic tape cartridge 310 is loaded to the recording/reproducing apparatus.
Further, the bottom plate 322a has protrusions 340 extending forwardly from the right and left ends; on the right and left protrusions 340, there are provided column-like tape guides 346 which extend vertically from the bottom plate 322a and which guide the magnetic tape 326 stretched between the reels 324 to the front side of the case body (cartridge case) by way of a predetermined route. Between the protrusions 340, the lower half 322 has no bottom plate 322a, forming an opening 328 of the case body.
The upper and lower halves 320 and 322, the outer lid 330, the upper lid 332, the inner lid 334, the upper and lower flanges of the tape reels 324, etc. are formed by injection molding. Apart from these, components formed by injection molding are used in the magnetic tape cartridge 310 as appropriate.
As described above, in the conventional magnetic tape cartridge 100 shown in FIGS. 16 through 19, the same spring (the coil spring 122) is used both as the reel lock spring for urging the reel lock member 112b and as the lid lock spring for urging the lid lock member 124; although this is advantageous from the viewpoint of reducing the number of parts, it involves more work compared with the case where the same spring is used both as the reel lock spring and as the lid lock spring when the assembly of the parts and the separated recovery thereof are taken into account. When the assembly takes a lot of work, the production efficiency deteriorates and the production cost increases. Further, the separated recovery of the parts is a bother, and it is likely that the components are recovered without being re-utilized; they will be destroyed before being disposed of, thus adversely affecting the environment.
Also, in the magnetic tape cartridge 204 having the reel lock mechanism as shown in FIGS. 20 and 21, its assembly requires the following complicated operations: the torsion spring 236 is previously fitted onto the center rod 222 with the inner surface of the upper half 200 facing upwards; further, the fitting shaft portion 224 of the reel lock member 216a or 216b is fitted onto the center rod 222, and the leg portions 234a and 234b of the torsion spring 236 are made to respectively abut the side wall 230 of the upper half 200 and the engagement arm portion 226 and, further, the braking claws 218a and 218b are engaged with the engagement teeth 219. Thus, the assembly is by no means easy.
Further, generally speaking, the magnetic tape cartridge is formed as a composite structure in which various metal components and resin components are combined in accordance with the requisite performance and configuration for the components or members. Examples of the synthetic resin used include: (1) resin molding of POM (polyacetal) for components of which wear resistance is required, (2) resin molding of PS (polystyrene) with Si (silicon) added in consideration of cost/performance, and (3) ABS (acrylic-nitrile-butadiene-styrene) resin in consideration of strength, ABS resin with PC (polycarbonate) added thereto, PC, PC with glass fiber added for reinforcement, etc.
For the spring members, etc., various metal materials are used in accordance with the requisite properties for the components. Also, regarding the members or components forming the reel lock mechanism, the reel lock members 216a and 216b, the center rod 222, etc. are formed of a resin material, such as POM, PAR (polyarylate), PC, or ABS resin, whereas the torsion spring 236 is formed of a spring metal material such as SUS (stainless steel). As for the other members, they are formed of synthetic resin, metal, or a composite material of metal and synthetic resin.
Thus, when the conventional magnetic tape cartridge is disassembled after use, and the components are divided into resin materials and metal materials for separate recovery, a rather complicated operation requiring considerable work and cost is involved to effect separate recovery for recycling for each material.
Recently, with increasing environmental awareness, attention has come to be focused on the influence of various wastes such as plastics or composite materials, and it is becoming increasingly important to involve little waste or not to cause contamination of the air, water, and earth even with the disposal, that is, to impose little load on the environment. In view of this, industrial products are required to be of a construction that allows application of recycling system.
In the case of the magnetic tape cartridges as shown in FIGS. 16 through 19 and FIG. 22, most of the components including the case body are formed of plastic, and metal material is only used where relatively large strength is required or where resiliency is required. Specifically, in these magnetic tape cartridges, the urging springs of the reel lock mechanism and the lid lock mechanism, that is, the reel lock springs and the lid lock springs, are formed of metal from the viewpoint of durability.
However, when disposing of such a magnetic tape cartridge after use, it is necessary to disassemble the magnetic tape cartridge and to extract the metal springs; this operation requires manpower.